mapping video onto open 3d rectangle

Hi there.
I hope somebody can help me with this. It's my first post after having used creative cow extensively as a source of reference for years. I did not find a post regarding this little challenge I have or perhaps I did not look in the right place; anyhow, any tips are appreciated:
I suspect I need to map a large video layer onto something that at least looks like a 3d object.
That object is a rectangular box, with the wall that's closest to the camera removed. If it was a room you'd see the left and right wall, the floor and ceiling and the back wall.
I want to map a video layer onto all visible surfaces. The image needs to go seamlessly over all 5 surfaces.
I have tried mocking it it up by pre-comping the relevant sections of the video layer and arranging them as 3dlayes in a master comp in the way described above (open box), but that leads to breaks in the image as the 'walls' cannot continue into the 'ceiling' (them being 2d objects). My hunch is that I have to map the video onto a simple 3d object, but how?
Thx,
Sven

Hi Ted.
Thx for that. I looked at those. They seem to explain how you can simulate camera moves for a still (or video Layer) that already display some sort of geometry or right angled walls and how to make those appear more 3D. It's not quite what I'd like to do unfortunately.
My imagery will just not show a room or alley (could be anything), but it has to take up the shape of the inside of a box - it will distort and that does not matter. Does that make sense? I have attached an image: you see that the image does not continue between the wall and the floor and ceiling respectively, but that is what I'd like - a bit like if you'd wrap an image around 5 sides of a cube
Thx,
Sven

I think you could use the new FreeForm Pro plugin if you have the budget for it. You can distort (bend) in 3d a simple cube spread (minus one face) to create your shape and then use Reflection Mapping to project your clip. I can't play with AE now, so i can't be sure.
On other idea I had was to actually import a 3d object using Zaxwerks Invigorator Pro, but I do not think you can use video as texture, only stills.

Ok. I played with freeform and I'm getting closer. It does some weird curving even though I have "tangent alignment" switched off - no sharp corners. However I think a 3d object will be best. I'll look into it. Thanks for your help.
Sven